The present disclosure relates to an imaging device such as a capsule endoscope, which performs transmission and reception of data and the like via radio communication, and to a transmission/reception system using the imaging device.
Recently, research and development of a capsule endoscope have been actively advanced. For example, the capsule endoscope has a capsule of 11 by 26 to 33 mm packaged with a light-sensing chip, a button battery, LED (Light Emitting Diode), CPU (Central Processing Unit), and a radio transmitter. Typically, such a capsule endoscope may shoot 2 to 35 images per second, and may shoot about 50 to 870 thousands of images in examination time of about 8 hours.
Data of the shot images are transferred as a real-time video signal by radio in a megahertz band from the capsule endoscope to an external portable receiver (data logger) via a radio-receiving antenna attached to a subject. Actually, eight or nine patch antennas are attached to a stomach region of the subject, and the image data are stored in a portable receiver carried by the subject.
A transmission/reception system including such a capsule endoscope includes a capsule endoscope as a transmission device introduced into a body cavity of a subject, a reception device for receiving data transmitted from the capsule endoscope, a recording medium in the reception device, and a display device. In the transmission/reception system, data of the internal images of the subject shot by the capsule endoscope are sequentially transmitted by radio in realtime, the data received via the plurality of antennas attached to the stomach region of the subject are recorded into the recording medium in the reception device, and after the data are acquired, the recording medium is transferred into a display device, or the data are displayed through cable communication or wireless communication (for example, see Japanese Unexamined Patent Application Publication No. 2009-189475 or No. 2009-153617). In addition, a system has been developed, where general-purpose PC (Personal Computer) acquires image data from a portable medical device via an insulation-compensating cable communication adaptor device using USB (Universal Serial Bus), a photocoupler, or a transformer (for example, see Japanese Unexamined Patent Application Publication No. 2009-178234).
However, these transmission/reception systems are expensive. In addition, since the antennas and the receiver are attached to a subject body, the subject has been significantly restricted in motion, leading to burden on the subject. Furthermore, the quantity of data transmission is limited, and image-shooting data may become imperfect in a portion such as an esophagus, through which the capsule endoscope moves fast. Moreover, since the transmission/reception systems are low in reception sensitivity, further development has been demanded